Bifunctional MOF‐Derived Carbon Photonic Crystal Architectures for Advanced Zn–Air and Li–S Batteries: Highly Exposed Graphitic Nitrogen Matters

Abstract

Nitrogen‐rich porous carbons (NPCs) are the leading cathode materials for next‐generation Zn–air and Li–S batteries. However, most existing NPC suffers from insufficient exposure and harnessing of nitrogen‐dopants (NDs), constraining the electrochemical performance. Herein, by combining silica templating with in situ texturing of metal–organic frameworks, a new bifunctional 3D nitrogen‐rich carbon photonic crystal architecture of simultaneously record‐high total pore volume (13.42 cm3 g−1), ultralarge surface area (2546 m2 g−1), and permeable hierarchical macro‐meso‐microporosity is designed, enabling sufficient exposure and accessibility of NDs. Thus, when used as cathode catalysts, the Zn–air battery delivers a fantastic capacity of 770 mAh gZn−1 at an unprecedentedly high rate of 120 mA cm−2, with an ultrahigh power density of 197 mW cm−2. When hosting 78 wt% sulfur, the Li–S battery affords a high‐rate capacity of 967 mAh g−1 at 2 C, with superb stability over 1000 cycles at 0.5 C (0.054% decay rate per cycle), comparable to the best literature value. The results prove the dominant role of highly exposed graphitic‐N in boosting both cathode performances.

Co−Ni Binary‐Metal Oxide Coated with Porous Carbon Derived from Metal‐Organic Framework as Host of Nano‐Sulfur for Lithium‐Sulfur Batteries

“…[28][29][30][31][32] For example, a Ni-based NiÀ MOF can effectively fix the polysulfide into the cathode structure with physical and chemical interactions synergistic effects, thereby enhancing the cycle performance of NiÀ MOF/S composite. [28][29][30][31][32] For example, a Ni-based NiÀ MOF can effectively fix the polysulfide into the cathode structure with physical and chemical interactions synergistic effects, thereby enhancing the cycle performance of NiÀ MOF/S composite.…”

Monodisperse Co9S8 nanoparticles in situ embedded within N, S-codoped honeycomb-structured porous carbon for bifunctional oxygen electrocatalyst in a rechargeable Zn–air battery

“…More interestingly, doping of carbon materials with highly electronegative heteroatoms, such as nitrogen can further significantly increase their conductivity by providing an advantageous channel for electron mobility [27][28][29][30] . In addition, doping with nitrogen heteroatoms will provide a strong polarization in the carbon matrix, resulting in an improved binding capacity of adjacent carbon to molecular oxygen and then enhanced ORR and OER activities [31][32][33] . In addition, the electronegativity of sulfur, close to carbon, is considered to be able to increase the exposed edge positions and disordered sites in carbon materials, such as graphene, which can enhance the electrochemical activity, stability, and alcohol resistance of carbon materials in alkaline medium [34][35][36][37][38] .…”

Applications of Metal–Organic‐Framework‐Derived Carbon Materials

“…Meanwhile, a low decay rate of 0.12% in every single cycle was realized within 300 cycles. Simultaneously, a new bifunctional 3D nitrogen‐rich carbon photonic crystal architecture with an extremely large surface area (2546 m 2 g −1 ) was designed by combining silica templating with in situ texturing of MOFs . The excellent rate performance is shown in Figure e, even when the rate increasing to 2 C, the bicontinuous hierarchical porous carbon obtained at 950 °C coated with sulfur (labeled as BHPC‐950@S) battery still delivers capacities as much as 967 mA h g −1 .…”